Multiple populations and species within the Atlantic seabob shrimp Xiphopenaeus kroyeri in the Guianan Ecoregion, South America: a molecular approach

Type:

Master Thesis subject (30 ECTS)

programme:

EMBC+

The Atlantic seabob shrimp Xiphopenaeus kroyeri is a highly exploited species in the tropical Western Atlantic. In the Guianan Ecoregion (Guyana, Suriname, French Guiana) the seabob shrimp is the target of several fisheries (artisanal as well as industrial). For a sustainable exploitation of the species it is crucial to know if the three countries target the same population of seabob shrimp or, as is now the assumption, different populations are being fished in the countries of the Guianan Ecoregion. Furthermore, genetic studies from Brazil indicate that X. kroyeri comprises at least two species, but the evidence is not overwhelming. If this is also the case in the Guianan Ecoregion is not known. This is however important in order to come to sustainable fisheries management and to avoid the overexploitation of the least abundant species.
The population structure and gene flow of X. kroyeri in the Guianan Ecoregion will be analysed using highly polymorphic genetic markers (microsatellites). To demonstrate the existence of multiple species, molecular analysis will be applied using a multilocus approach. In previous studies on X. kroyeri only the mitochondrial marker COI was used, limiting the certainty of species delimitation. By using both nuclear and mitochondrial gene sequences in this research, species delimitation will be supported with far greater accuracy.
Note that seabob samples from the Guianan Ecoregion will already be available from a sampling campaign in spring 2016. Practical work will consist of DNA extraction and amplification of gene regions of interest by PCR. A good deal of work will consist of analysis of the genetic data. The research will be executed in the molecular lab of the Marine Biology Research group (UGent), in close cooperation with the Aquatic Environment and Quality research group (ILVO) and the Laboratory of Biodiversity and Evolutionary Genomics (KUL).
If interested, the genetic analyses can be combined with a detailed morphological investigation, with the aim to distinguish the different species.